Dinosaur “Mummies” Reveal Edmontosaurus Had Hooves, Delicate Skin – And Resembled Ancient Cows
WYOMING – Newly analyzed fossilized remains of Edmontosaurus, a duck-billed dinosaur that roamed North America 66 million years ago, are rewriting our understanding of dinosaur skin and locomotion. Remarkably preserved “mummies” discovered in east-central Wyoming reveal the herbivore possessed hooves – a trait previously thought exclusive to mammals – along with delicate, wrinkled skin covered in small scales and a distinctive ridge along its back.
The exceptional preservation, thanks to a layer of fine clay, offers an unprecedented glimpse into the life of this common Cretaceous herbivore. “It is indeed the first dinosaur, the first reptile and the first land vertebrate known to have developed hooves,” scientists point out, demonstrating a phenomenon called convergent evolution where different species independently develop similar traits to adapt to similar environments.
Edmontosaurus was a large animal, reaching approximately 12.8 meters (42 feet) in length as an adult – rivaling the size of Tyrannosaurus rex. The fossils show evidence of a fleshy ridge running along the neck and back, a row of spines down the tail, and delicate wrinkles over the ribcage. Researchers also noted the dinosaur’s skin was thin enough to reveal these details and was covered in small scales.
Paleontologist Paul Sereno of the University of Chicago,a study author,jokingly remarked,”Sorry,mammals,after all,you weren’t the ones who invented hooves.” He explained the hooves were likely an adaptation for efficient walking and running on hard ground.
The abundance of Edmontosaurus fossils in the fossil record has led researchers to believe they lived in massive herds. Sereno describes edmontosaurus as “the cow of that time,” coexisting with predators like Tyrannosaurus and other herbivores such as Triceratops and Ankylosaurus. Fossil evidence, including tooth marks on Edmontosaurus remains, confirms they were a frequent food source for T. rex.
